There is still a 'prime' self that is largely disconnected from the rest. It's not really his weak point. It's more sentimental. It's the avatar that does the most traveling. You can spot it at a glance from his constant companions, his direwolves Hati and Skoll.

Hati and Skoll are complicated beasts, the brothers having been former shamanistic mages that sought Ark out to try and kill, as many mages do. He really wasn't up to killing anyone that day, so he converted them instead. Warped their bodies into hulking direwolves.